Re: Avoid global state in arm_handle_option

[Richard Earnshaw <rearnsha@arm.com>]

On Thu, 2011-04-07 at 22:06 +0000, Joseph S. Myers wrote:
> This patch stops the ARM handle_option hook from using global state -
> in fact removing the hook altogether by using .opt Enum facilities for
> what it did.
> 
> The -march, -mcpu and -mtune option values are made to use Enum.  The
> Enum definitions go in a new generated file arm-tables.opt; for
> -mcpu/-mtune these are generated from the existing arm-cores.def.  For
> -march, since there was no enum for architecture values nor any
> apparent need for one, and given the .def arrangements already used
> for core names, I added a new arm-arches.def with the architecture
> table.  In both cases, giving a help text on the Enum definitions
> meant that generic code could do what arm_target_help previously did,
> so that hook is also removed (the only implementation of the
> TARGET_HELP hook is now for AVR).
> 
> arm_selected_* are now set at the start of arm_option_override.  When
> I turn to dealing with global state in those hooks (and splitting the
> parts needing global state into a separate hook) I expect to make
> arm_selected_* purely local variables of arm_option_override, rather
> than moving them to the gcc_options structure.  The only place they
> are used outside that function is arm_file_start, and const char *
> fields in the gcc_options structure can be added for those particular
> uses.
> 
> Tested building cc1 and xgcc for cross to arm-eabi.  Will commit to
> trunk in the absence of target maintainer objections.
> 
> contrib:
> 2011-04-07  Joseph Myers  <joseph@codesourcery.com>
> 
> 	* gcc_update (gcc/config/arm/arm-tables.opt): New dependencies.
> 
> gcc:
> 2011-04-07  Joseph Myers  <joseph@codesourcery.com>
> 
> 	* config.gcc (arm*-*-*): Add arm/arm-tables.opt to extra_options.
> 	* config/arm/arm-arches.def: New.
> 	* config/arm/arm-opts.h: New.
> 	* config/arm/genopt.sh: New.
> 	* config/arm/arm-tables.opt: New (generated).
> 	* config/arm/arm.c (arm_handle_option, arm_target_help,
> 	TARGET_HANDLE_OPTION, TARGET_HELP, arm_find_cpu): Remove.
> 	(all_architectures): Get most table contents from arm-arches.def.
> 	(arm_option_override): Set arm_selected_arch, arm_selected_cpu and
> 	arm_selected_tune here.
> 	* config/arm/arm.h (enum processor_type): Move to arm-opts.h.
> 	* config/arm/arm.opt (config/arm/arm-opts.h): New HeaderInclude.
> 	(march=, mcpu=, mtune=): Use Enum and Var.
> 	* config/arm/t-arm ($(srcdir)/config/arm/arm-tables.opt): New.
> 	(arm.o): Update dependencies.

OK.

R.